There are known cutting insert holders which are adjustable and designed to hold carbide cutting inserts used in machine tool metalworking operations. The carbide cutting inserts are disposed of after repeated use, and the cutting insert holder is used as a single purpose tool only. Examples of these type of cutting insert holders are disclosed in U.S. Pat. No. 4,850,757 to Stashko, and in U.S. Pat. Nos. 4,125,342 to Kress and 4,279,550 to Kress et al. These patents feature various designs for clamping the insert, although not allowing for direct adjustment of the insert orientation within the holder. The Stashko patent discloses an arrangement allowing for radial adjustment of the insert as needed in the metalworking process.
Typically, repeated use of the cutting insert working edge causes it to become worn down, to a point where its useful life is over, and the insert is then discarded. At this point, the edges of the insert are used up as they are either chipped, burnt or blunted. For example, with a triangular carbide cutting insert, there may be useful life remaining in the carbide material behind the "used up" edge, to the theoretical inner circle, on 3 or 6 edges (if the insert is turned over). However, existing cutting insert holders are generally not designed for multipurpose applications nor are they designed to exploit the remaining useful life since they do not provide the orientation required to hold the used insert and expose carbide material which is still useful.
Standard insert holders are designed to clamp the cutting insert in one position only for single applications with maximum support under the cutting edge, with little or no possibility of regrinds or readjustment for other applications.
Therefore, it would be desirable to provide a triangular carbide cutting insert holder for re-use of used triangular carbide cutting inserts that can be adjusted for multipurpose machining operations.